Step-1: To a solution of 1-(tert-butoxycarbonyl)-1,2,3,4-tetrahydroquinoline-2-carboxylic acid (100 mg, 0.36 mmol) in anhydrous DMF (3 ml) was added EDC.HCl (207 mg, 1.08 mmol), HOBt (73.4 mg, 0.54 mmol) and triethylamine (0.08 ml, 0.54 mmol) at RT and the mixture was stirred for 10 min. To this reaction mixture, 2,3-diaminobenzamide (60 mg, 0.4 mmol) was added and heated to 55° C. over night. The reaction mixture was poured into ice cold water and stirred for 30 min. The precipitate formed was filtered and dried under vacuum to yield benzyl 2-((2-amino-3-carbamoylphenyl)carbamoyl)-3,4-dihydroquinoline-1(2H)-carboxylate. MS (ES+): m/z 2411.30 [M+H]+
